The engine and gearbox were in pretty good condition already before the project started. Putting the engine and gearbox back together should be pretty straightforward. But of course when you start taking things apart you usually find at least a problem or two. No exceptions here…
We took the cylinder head completely apart to inspect all the components. All in all things looked pretty good, but there were a few issues. The necks on the camshaft seat looked somewhat worn so we replaced it with a better one from a Saab Petro head we had as a spare.
The cylinder head itself was in good condition. No cracks no warping.
But there was damage to a few of the exhaust valves. The necks on them looked badly burned or maybe corrosion caused by water. This is a common place for the B-Turbo exhaust valves to break with potential for major engine damage.
Thankfully I had a few new valves in stock. The B-Turbo exhaust valves are different from the non-turbo valves. They are sodium filled for better heat transfer and cooling.
The valve seats were hand ground to ensure a tight seal.
The lifter clearance is adjusted by small blocks of varying thicknesses. It’s a somewhat time consuming process since you need to put together and take apart the valve mechanism a few times to get the clearances right.
Turbo or not?
So what’s the difference in the cylinder head between the Turbo and the naturally aspirated engines? The non-turbos have restrictions on the intake valve seats. The non-restricted heads were used on the Turbo and Saab Petro. Petro also used the low compression pistons from the Turbo.
We test fitted most of the components to make sure we had all the right nuts, bolts and washers where they needed to be. I would have liked to install new timing chain guides but couldn’t source any. The ones that were in the engine were in decent condition, but it would have made sense to put in new ones while the engine was already in pieces.
Putting the engine back together was pretty straight forward. The most important thing being to check the timing marks on the chain.
We used a quality sealer to hopefully make sure the engine doesn’t leak oil…
Also all the accessories were cleaned up and put back together. Here’s the throttle body. New cold start (and extra enrichment) valve and dashpot.
As already mentioned there was not much done to the gearbox. It was cleaned inside and out and some freshly zinc coated components and drive shaft seals installed.
Next it was time to marry the engine and the box. New gasket and also sealer to make sure there are no leaks. Some of the bolt threads go straight through to the oil reservoir so they need thread sealer applied.
There we go – almost time to drop it into the engine bay.